#include <stdio.h>
#include <ctype.h>
#include <string.h>
#define LEN 3
void flip(int len, double *a);

int main()
{
    double a[LEN] = {1.0, 2.0, 3.0};
    for (int i = 0; i < LEN; i++)
        printf("%f ", a[i]);
    printf("\n");
    flip(LEN, a);
    for (int i = 0; i < LEN; i++)
        printf("%f ", a[i]);
    return 0;
}
void flip(int len, double *a)
{
    int temp;
    for (int i = 0; i < len / 2; i++)
    {
        temp = a[i];
        a[i] = a[len - i - 1];
        a[len - i - 1] = temp;
    }
}